Microstructure and ferroelectricity of barium titanate thin films on Si for integrated photonics

Significant progress has been made in integrating novel materials into silicon photonic structures to extend the functionality of photonic circuits. One of these promising optical materials, BaTiO
₃
(BTO), exhibits a large Pockels coefficient as required for high-speed light modulators. Here, we employ several deposition methods such as molecular beam epitaxy and chemical vapor deposition to realize BTO thin films with different morphology and crystalline structure. By identifying the key structural predictors of electro-optic response in BTO/Si, we provide a roadmap to fully exploit the linear electro-optic effect in novel hybrid oxide/semiconductor nanophotonic devices.